| The rapid development of pipeline construction has brought new challenges to pipeline safety inspection,especially industrial pipelines,which have been in the state of high temperature and high pressure,toxic and harmful,flammable and explosive liquid and gas for a long time,once the pipeline is damaged,small leakage accidents will lead to a waste of re the research on pipeline non-destructive testing,and will has great significance.At present,there are a variety of pipeline detection technologies,but for some special pipelines,their collection environment is complex,the collection of information is disturbed,and some detection techniques are often limited.Therefore,the industrial pipeline image based on endoscope video is studied in this paper.the main task of the research is to select the key frame from the endoscope video shot of the inner wall of the pipeline and transform the key frame into a clearer plane unfold drawing.Through the above operations to provide technical support for this kind of pipeline detection.In order to obtain the two-dimensional plane unfold drawing of the industrial pipeline,firstly,an acquisition platform composed of PLC,stepper motor,power amplifier circuit and endoscope was built,which is used to collect video images inside the pipeline.Secondly,the endoscope imaging model was established,and the main point parameters of the endoscope were obtained by studying the relationship between the posture of the endoscope and the imaging of the inner wall of the pipe,and combining with Zhang Zhengyou's calibration method,which lays the foundation for the extraction,correction and expansion of the effective circle of the subsequent image.Thirdly,aiming at the problems of uneven light and low overall illuminance of the video image,an improved low illuminance image enhancement algorithm based on BEMD was proposed to enhance the contour information of the flaw detection area.Then,the local iterative improved segmentation algorithm based on Otsu method was used to segment the internal flaw detection area of the pipeline to expand the effective region of the key frame.Finally,an improved radial expansion algorithm was proposed on the basis of the effective ring region of the key frame to realize the tangential and radial expansion of the torus,so as to obtain the inner plane unfold drawing of the pipeline. |
